Question

Metabolism Essay Question (10 pts)

According to the law of conservation of matter, matter is neither created nor destroyed. This means that the same number and type of atoms exist after a chemical change as were present before the chemical change.

So . . .

A. When someone goes on a diet and loses weight, what happens to the body fat that they lose? Where does it go? What do the molecules of fat turn into? (5 pts)

HINT: If you are tempted to say that it “turns into energy” STOP! Matter does NOT “turn into” energy. Energy can be released during chemical reactions . . . but the atoms are still there, just rearranged into different (and usually smaller) molecules!

B. How would going on a diet that severely restricted carbohydrate intake affect the answer to Part A above? Explain your answer! (5 pts)

HINT: See the section on “Lipolysis” on page 1011 in your textbook and think about the following questions:

• How and why does carbohydrate availability affect lipid digestion?

• How will this change the end products?

Answer 1

A . The body fat that the person looses because of his diet plan is converted into water and carbon dioxide

If 1kg fat is lost -- 0.16 kg Water is produced - It enters the blood circulation and is eliminated through urine

-- 0.84 kg carbon dioxide is produced - exhaled through the lungs

B . Due to low carbohydrate diet ,the person use glycogen for producing energy which is stored in liver .hence he looses weight .

Carbohydrate availability affect the lipid digestion . This is because the carbohydrates are utilised for body needs and therefore lipids are not digested and are stored .

This leads to the accumulation of fats (lipids) . Therefore end products will be fats